27th February 2025

Increased bone turnover

Osteoclastic bone resorption may be directly promoted by hyperthyroidism, malignancies, e.g. multiple myeloma or metastases to bone, and prolonged immobilisation (e.g. after spinal cord injuries). Osteoblastic bone formation is depressed with prolonged immobilisation, and accounts for the hypercalcaemia seen in immobilised patients with Paget’s disease of bone (whose high bone turnover state otherwise does not cause hypercalcaemia).

Image source: Wikimedia Commons (2020). Emmentalersign, Licensed under a Creative Commons licence. Available for free at: https://commons.wikimedia.org/wiki/File:Emmentalersign_.jpg (Accessed: 24 January 2024). Image source: BioMed Central Ltd (2009). Abdominal radiograph showing osteoblastic changes of spine, pelvic and femoral bones (arrows)., Licensed under a Creative Commons licence. Available for free at: https://casesjournal.biomedcentral.com/articles/10.1186/1757-1626-2-54/figures/2 (Accessed: 24 January 2024).